<!DOCTYPE html>
<html lang="zh">

<head>
    <title></title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <script src="https://unpkg.com/vue/dist/vue.js"></script>
    <link href="../css/style.css" rel="stylesheet"> </head>
<body>
<div id="myApp">
    <h1>用户注册</h1>
    
    <div>
        <label for="username">用户：</label>
        <input type="text" id="username" v-model.lazy="username" @change="checkUsername">
        <span v-if="checkUsernameOK">可注册</span>
    </div>
    <div>
        <label for="age">年龄：</label>
        <input type="number" id="age" v-model.number="age">
    </div>
    <div>
        <label for="content">个人简介：</label><br/>
        <textarea id="content" v-model.trim="content" cols="55" rows="8"></textarea>
    </div>
    
    <h4>信息区</h4>
    <p>{{username}}</p>
    <p>{{age}}</p>
    <p><pre>{{content}}</pre></p>
</div>
<script>
    var myApp = new Vue({
        el: '#myApp', 
        data: {
            username: "",
            checkUsernameOK: false,
            age: "",
            content: "",
        },
        methods: {
            checkUsername: function(){
                if (this.username.length > 0) this.checkUsernameOK = true;
                else this.checkUsernameOK = false;
            },
        },
    });
</script>
</body>

</html>